Electrical relay



May 22, 1934.

H. E. ASHWORTH I ELECTRICAL RELAY Filed Aug. 19, 1935 0 MW 5 FCC. B W 2 101A it? C 4 a 2 S. l EM N 651 mi 0.. g 0.. P

Mag/29$ R v. m m W 0 E T W I IS A T E 6 9mm P P G Y B 10? 7 a m Patented May 22, 1934 UNZTED ELECTRICAL RELAY Harry E. Ashworth, Swissvale, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application August 19, 1933, Serial No. 685,845

14 Claims.

My invention relates to electrical relays.

I will describe two forms of electrical relays embodying my invention, and will then point out the novel features thereof in claims.

5 In the accompanying drawing, Fig. l is a View, partly diagrammatic, showing one form of relay embodying my invention. Fig. 2 is a view showing, in isometric projection, a modified form of the relay illustrated in Fig. 1, and also embodying my invention.

Referring first to Fig. l, the relay in the form here shown comprises an electromagnet A of the usual type having two parallel cores l" and 1 connected together at their upper ends by a backstrap 2 and provided at their lower ends with enlarged pole pieces 3 and 3 respectively. The core 1 carries the usual operating winding 4 and the core 1 carries a similar operating winding 4 The windings 4 and 4 are conneoted in series in the usual manner in a circuit which includes a battery 13 and a switch C.

' The relay also comprises a permanently magnetized core 5, the upper end of which engages the underside of an extension 2 of the backstrap 2, and the lower end of which is provided with an enlarged pole piece 5 As here shown, the core 5 is a permanent magnet, but this core might, of course, equally well be a magnetizable core which is constantly magnetized by a suitable windng in the well known manner.

The relay further comprises a neutral armature 6 which underlies the pole pieces on all three cores, and which is pivotally supported intermediate its ends by means of pivot pins '7 carried by a non-magnetizable bracket '7 secured to the pole piece 3 only one pivot pin being visible in the drawing because the other pivot pin is directly back of the one shown. The parts are so proportioned that the armature 6 is biased by 40 gravity to the position shown, in which position the left-hand end of the armature is swung toward the pole piece 5 and the right-hand end of the armature is swung away from the pole pieces 3 and 3 The armature, however, is

adapted to be rotated, in response to energization of the electromagnet A, from the position shown to another extreme position, in which latter position the left-hand end of the armature is separated from the pole piece 5* by a relatively large air gap and the right-hand end of the armature is separated from the pole pieces 3 and 3 by relatively small air gaps, as will be explained more fully hereinafter. ttached to the underside of the armature 6, by means of an insulating support 8, is a fixed contact finger 9 which engages a fixed contact 9 to close a back contact 9-9 or a fixed contact 9 to close a front contact 9-9 according as the armature occupies the extreme position shown or its other extreme position.

The parts are so arranged that when the switch C is closed, the flux which is set up in cores 1 and I by the current supplied to windings 4 and 4 from battery C will cause the upper end of core 1 to have the same polarity as the upper end of core 5, and for purposes of explanation, I will assume that core 5 is magnetized in such manner that its upper end is a north magnetic pole. With the relay constructed in this manher, it will be apparent that when switch C is open, the greater part of the flux from core 5 will flow from the upper end of this core through extension 2 of backstrap 2, core 1 pole piece 3 the air gap between pole piece 3 and armature 6, armature 6, the air gap between armature 6 and pole piece 5 and pole piece 5" back to the lower end of core 5, thus exerting a torque on armature 6 which urges it to, and holds it in, the position shown. When, however, switch C becomes closed, the flux which is then set up in ores 1 and l by the current in windings 4 and 4 will traverse the core 1 in the direction opposite to that from the core 5, and the parts are so proportioned that this flux will have a greater magnitude than the flux from core 5. As a result, the flux threading armature 6 due to core 5 becomes greatly decreased, so that the torque exerted on the armature tending to hold the armature in the position shown is greatly decreased. Furthermore, the flux set up in the cores l and 1 under these conditions, due to the current in windings 4 and 4 exerts a relatively large torque on armature 6 in the direction opposite to that exerted on the armature by the flux from core 5, and the armature 6 therefore now swings from the position shown to its other extreme position, thus opening contact 99 and closing contact 9-9 As was previously pointed out when armature 6 is swung to its other extreme position, the air gap between the pole piece 5 and the lefthand end of the armature is relatively large, and it will be apparent, therefore, that when switch C is subsequently opened to deenergize the relay, the armature 6 will have substantially the same release characteristics as it would have if core 5 were not provided.

Referring now to Fig. 2, in the modified form of the relay here shown, the windings 4 and 4 are connected with battery B over a pole changer P, and the relay is provided withan additional and 3 permanently magnetized core, designated by the reference character 10, and with an additional armature designated by the reference character 11. The core 10 is secured at its upper end to the extension 2*. of the backstrap 2, and is provided at its lower end with an enlarged pole piece 10*. The core 10 is so disposed that the pole piece 10 will have a polarity opposite to that of the pole piece that is to say, assuming that the pole piece 5 is a south pole, as shown, the pole piece w will be a north pole. The armature 11 underlies the pole pieces 3 and 3 and the pole piece and is pivotally attached intermediate its ends to the pole piece 3 in the same manner that armature 6 is pivotally attached to the pole piece 3 and it will be apparent, therefore, that armature 11 is biased by gravity to the position shown, in which position'its left-handend is swung toward the pole piece 10 and its righthand end is swung away from the pole piec'e's 3 The armature 11, however, is adapted to be moved, under certain conditions, which will be described hereinafter, to another position in which its left-hand end is swung away from the pole piece 10 and its right-hand end is swung toward the pole pieces 3 and 3. Attached to the underside'of the armature 11 by means of an insulated support 12 is a contact finger 13 which cooperates with two fixed contacts 13 and 13 in the samemanner that the contact finger 9 cooperates with the fixed contacts 9 and 9.

With the relay constructed in the manner just described, when the pole-changer P occupies the position in which the windings 4 and 4 are both deenergized, as shown in the drawing, flux from the permanently magnetized cores 5 and 10 traverses a path including core 10, pole piece 10*, the air gap between pole piece 10 and armature l1, armature 11, the air gap between armature 11 and pole piece 3 pole piece 3*, the air gap between pole piece S -and armature 6, armature 6, the air gap between armature '6 and pole piece 5 pole piece 5 core 5, and extension 2 of backstrap 2. The permanent magnet flux traversing this path creates a torque on both armature 6 and ll which urges these armature to, and holds them in, the position shown.

I will now assume that pole-changer P is moved to the position in which windings 4 and 4 become energized in such manner that pole piece 3 becomes a north pole and pole piece 3 be-' comes a south pole; Under these conditions, pole pieces 3 and 5 will have the same polarity, while pole pieces 3 and 10 will havedifierent polarities. It will be apparent that when pole pieces 3 and 5 have the same polarity, flux will not flow from pole piece 3 to pole piece 5 through the armature 11 in the manner previously described, and the magnitude of the permanent magnet flux threading armature 6 will therefore become considerably decreased, with the result that armature 6 will rotate from the extreme position shown to its other extreme position, in

substantially thesame manner as was previously described in describing Fig. 1. It will also be apparent that when pole pieces 3 and 10 have different polarities, flux from core 10, and'a part of the flux due to the current in winding 4 will flow from pole piece 10 to pole piece 3 through armature 11, and will thus create a torque on armature 11 which tends to hold this latter armature in the position shown. Flux will also flow from pole piece 3 to pole piece 3 through armature 11 under these conditions, and will thus exert a torque on the armature tending to rotate the armature away from the position shown. This latter flux, however, will have a.

relatively small magnitude due to the relatively large air gap between the core 3 and the armature 11, and also due to the fact that as soon as armature 6 becomes picked up, this armature provides a low resistance path from the pole piece 3 to the pole piece 3 which shunts most of this latter flux away from armature 11. It will be apparent, therefore, that the torque exerted on the armature 11 tending to hold the armature in the position shown will be considerably greater than that tending to move it away from this position, and since this torque is assisted by gravity, it follows that the armature 11 will remain in the position shown.

I will next assume that pole-changer P is operated to reverse the polarity of the current supplied to windings 4 and 4 Under these conditions, pole piece 3 will be a north pole, and will, therefore, have the same polarity as pole piece 10 but a different polarity from pole piece 5 As a result, armature 11 will now move from the position shown to its other position,pwhile armature 6 will be held in the position shown, in i a manner which will be apparent from an inspection of the drawing and from the foregoing without further description.

I have found by actual test that relays constructed in accordance with my invention have .1

the main electro-magnet, as has heretofore been I customary, and the chief advantage of relays em bodying my invention lies in this improvement in the operating characteristics of the relay.

Another advantage of relays embodying myinvention is that their structure is simple in design and therefore easy to assemble'and manufacture.

A further advantage of relays embodying my invention is that they providean eiiicient and safe arrangement for preventing the back contacts of the relay from jarring open due to vibration when the relay is deenergized.

Although I have herein shown and described only two forms of electrical relays embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. An electrical relay comprising an electromagnet and'a permanent magnet, and an armature pivotally supported in such manner that if it is swung toward said electromagnet it will be swung away from said permanent magnet and vice-versa, said two magnets being connected together by a magnetizable member in such manner that when said electromagnet becomes energized the resultant flux which is set up opposes the flow of flux to said armature from said permanent magnet.

2. A relay comprising two magnetizable cores and a constantly magnetized core connected togather at one end by a backstrap and each provided at the other end with a pole piece, an armature pivotally supported in such manner that it is biased to one position and that if it is rotated in one directon from said one position it will move toward the pole pieces on said magneti able cores and. away from the pole piece-on said constantly magnetized core, and windings disposed on said magnetizable cores in such manner that when said windings are energized the resultant flux which is set up in said magnetizable cores will act to decrease the flux which threads said armature due to said constantly magnetized core.

3. A relay comprising two magnetizable cores and a permanently magnetized core connected together at one end by a backstrap and each provided at the other end with a pole piece, said three cores being disposed in the same plane in such manner that the one magnetizable core is between the two remaining cores, an armature pivotally supported intermediate its ends in such manner that if said armature is rotated about its pivot in one direction the one end will swing toward the pole pieces on said magnetizable cores and the other end will swing away from the pole piece on said permanently magnetized core, and windings associated with said magnetizable cores in such manner that when said windings become energized the resultant flux which is set up in said magnetizable cores will oppose the flux which threads said armature due to said permanent magnet.

4. A relay comprising two magnetizable cores and a constantly magnetized core connected to gether at one end by a backstrap and each provided at the other end with a pole piece, an armature pivotally supported in such manner that it is biased to one position and that if it is rotated in one direction from said one position it will move toward the pole pieces on said magnetizable cores and away from the pole piece on said constantly magnetized core, windings disposed on said magnetizable cores in such manner that when said windings are energized the resultant flux which is set up in said magnetizable cores will act to decrease the flux which threads said armature due to said constantly magnetized core, and a contact controlled by said armature.

5. A relay comprising two magnetizable cores and a constantly magnetized core connected together at their upper ends by a backstrap and each provided at the other end with a pole piece, said three cores being disposed in the same plane with the one magnetizable core between said constantly magnetized core and the other magnetizable core, an armature pivotally supported intermediate its ends for rotation about a horizontal axis in such manner that if said armature is rotated about its pivot in one direction the one end will swing toward the pole pieces on said magnetizable cores and the other end will swing away from the pole piece on said constantly magnetized core, and two windings disposed on said two magnetizable cores respectively and connected in series in such manner that when current is supplied to said windings the upper end of said middle core will have the same polarity as the upper end of said constantly magnetized core.

6. A relay comprising two magnetizable cores and a constantly magnetized core connected together at one end by a backstrap and each provided at the other end with a pole piece, said cores all being disposed in the same plane with the one magnetizable core located between the two remaining cores, an armature pivotally supported intermediate its ends in such manner that it is biased to one position in which one end is swung toward the pole piece on said constantly magnetized core and the other end is swung away from the pole pieces on said magnetizable cores but is movable to another position in which said other end is swung toward the pole pieces on said magnetizable cores and said one end is swung away from the pole pieces on said constantly magnetized core, and windings on said magnetizable cores so arranged that when said windings are energized the pole piece on said middle core has the same polarity as the pole piece on said constantly magnetizable core, whereby when said windings are deenergized there is a threading of the flux from the constantly magnetized core through the middle core and the armature to produce a torque which urges the armature to its biased position but that when said windings are energized the flux from said constantly magnetized core is prevented from threading said middle core so that the torque on said armature due to the flux from said constantly magnetized core is then materially decreased.

7. A relay comprising two magnetizable cores connected together at one end by a backstrap and each provided at the other end with a pole piece, windings on said magnetizable cores for at times energizing said cores, two oppositely disposed permanently magnetized cores connected at one end with an extension of said backstrap and each provided at the other end with a pole piece, a first armature coacting with the pole pieces on said magnetizable cores and with the pole piece on one of said constantly magnetized cores, and a second armature coacting with the pole pieces on said magnetizable cores and with the pole piece on the other constantly magnetized core.

8. A relay comprising two magnetizable cores connected together at one end by a backstrap and each provided at the other end with a pole piece, windings on said magnetizable cores for at times energizing said cores, two oppositely disposed permanently magnetized cores connected at one end with an extension of said backstrap and each provided at the other end with a pole piece, a first pivoted armature coacting with the pole pieces on said magnetizable cores and with the pole piece on one of said constantly magnetized cores in such manner that when said armature is rotated in one direction about its pivot it will swing toward the pole pieces on said magnetizable cores and away from the pole piece on said one constantly magnetized core, and a second pivoted armature coacting with the pole pieces on said magnetizable cores with the pole piece on the other constantly magnetized core in such manner that when said armature is rotated in one direction about its pivot it will swing toward the pole pieces on said magnetizable cores and away from the pole piece on said other constantly magnetized core.

9. A relay comprising two magnetizable cores connected together at one end by a backstrap and each provided at the other end with a pole piece, windings on said magnetizable cores for at times engaging said cores, two oppositely disposed permanently magnetized cores connected at one end with an extension of said backstrap and each provided at the other end with a pole piece, a first armature pivotally supported in such manner that it will swing toward the pole pieces on said magnetizable cores and away from the pole piece on one of said constantly magnetized cores or vice versa according as said armature is rotated in one direction or the other about its pivot, and a second armature pivotally supported in such manner that it will swing toward the pole pieces on said magnetizable cores and away from the pole piece on the other constantly magnetized liO rotated in one direction or the other about its pivot.

10. A relay comprising two magnetizable cores "connected together at one end by a backstrap and each provided at the other end with a pole piece, windings on said magnetizable cores for at times energizing said cores, two oppositely disposed permanently magnetized cores connected at one end with an extension of said backstrap and each provided at the other end with a pole piece, a first armature pivotally supported in such manner that it is biased by gravity to a first position in which it is swung away from the pole pieces on said magnetizable cores and toward the pole piece on one of said constantly magnetized cores, said first armature being movable to a second position in which it is swung toward the pole pieces on said magnetizable cores and away from the pole piece on said one magnetizable core, and a second armature pivotally supported in such manner that it is biased by gravity to a first position in which it is swung away from the pole pieces on said mag'netizable cores and toward the pole piece on the other permanently magnetized core, said second armature being movable to another position in which it is swung toward the pole pieces on said magnetizable cores and away from the pole piece on said other permanently magnetized core.

11. A relay comprising an electromagnet consisting of two magnetizable cores connected together at one end by a backstrap and provided with the usual energizing winding, two oppositely disposed permanent magnets connected at one end to an extension of said backstrap, and two armatures one controlled by said electromagnet and one of said permanent magnets and the other controlled by said electromagnet and the other permanent magnet.

12. A relay comprising two magnetizable cores connected together at one end by a backstrap and provided at the other end with pole pieces, two windings one on each of said cores, means for supplying said windings connected in series with current of one polarity or the other, two oppositely disposed permanent magnets connected at one end to an extension of said backstrap and each provided at the other end with a pole piece, a first armature pivotally mounted intermediate its ends in such manner that it is biased by gravity to one position in which one end is swung toward the pole piece on one of said permanent magnets and the other is swung away from the pole pieces on said magnetizable cores, said first armature being movable to another position in which said one end is swung away from the pole piece on said one permanent magnet and said other end is swung toward the pole pieces on said magnetizable cores, and a second armature pivotally mounted intermediate its ends in such manner that it is biased by gravity to one position in which one end is swung toward the pole piece on the other permanent magnet and away from the pole pieces on said magnetizable cores, said second armature being movable to another position in which said one end is swung away from the pole piece on said other permanent magnet and said other end is swung toward the pole pieces on said 'mag'netizable core.

13. A relay comprising two r'nagnetizable cores and a constantly magnetized core connected together at one end by a backstrap and each provided at the other end with a pole piece, an armature pivotally mounted intermediate its ends in such manner that it is biased by gravity to a first position in which one end is swung toward the pole piece on said constantly magnetized core and the other end is swung away from the pole pieces on said magnetizable cores but movable to a second position in which said one end is swung away from the pole piece on said constantly magnetized core and said other end is swung toward the pole pieces on said magnetizable cores, and means for at times setting up a flux in said magnetizable cores. 7 V

14. A relay comprising two magnetizable cores and a constantly magnetized core connected together at one end by a backstrap and each provided at the other end with a pole piece, an armature pivotally mounted intermediate its ends in such manner that it is biased by gravity to a first position in which one end is swung toward the pole piece on said constantly magnetized core and the other end is swung away from the pole pieces on said magnetizable cores but movable to a second position in which said one end is swung away from the pole piece on said constantly magnetized core and said other end is swung toward the pole pieces on said magnetizable cores, two windings one on each of said magnetizable cores, and means for supplying said windings connected in series with current of one polarity or the other.

HARRY E. ASHWORTH. 

